Suspension device and suspension system

ABSTRACT

A suspension device for a connecting component ( 5 ) to which a dynamic load is mountable and which forms at least one eye, the suspension device comprising an axis ( 2 ) fixed to a carrier ( 1 ), a roller ( 3 ) rotatably mounted on the axis ( 2 ) and having a circumferential groove into which the connecting component ( 5 ) can be hooked in frictionally, and at least one safety device ( 4 ) adapted to be moved manually from a locking position, in which it prevents a hooking-in or hooking-off of the connecting component ( 5 ), into a release position permitting a hooking-in or hooking-off of the connecting component ( 5 ).

The present invention relates to a suspension device for a connectingcomponent to which a dynamic load, such as a swing, is mountable, and toa suspension system comprising the suspension device and the connectingcomponent.

Currently, there are two suspension systems that are used for suspendingswings.

On the one hand, there is the classical hook or ring, which is firmlymounted on the ceiling and into which a load to be borne, such as aswing, is simply hooked in. In this construction, a load is suspended ona karabiner or the like, said karabiner being hooked into the hook/ringand rolling off on the bent inner circumferential surface of thehook/ring due to an oscillating movement of the load.

Although this suspension system leads to satisfactory oscillatingproperties, it is disadvantageous in that, when the load performs anoscillating movement, the hook/ring is subject to a strong bendingstress that may lead to material fatigue. The consequence may be abreaking of the hook/ring at its weakest point.

On the other hand, suspension devices having integrated mobile jointsare known. They offer a high load-carrying capacity and a high level ofsecurity against dynamic loads, and the forces occurring are directlytransferred into the ceiling/wall. However, these suspension devicesinvolve the disadvantage that a quick hooking-in and hooking-off of aload, such as a swing, is not possible without the use of tools.Furthermore, these device show a comparably high internal friction, i.e.the conservation of the kinetic energy is comparatively low, reducing amaximum duration of the oscillating movement, which is undesirable inthe case of a swing, in particular.

The documents DE 198 21 701 A1, EP 0 520 935 A1, U.S. Pat. No. 1,207,985A and DE 80 05 495 U already describe various suspension devices for adynamic load. However, these documents do not show any safety deviceadapted to be moved manually from a locking position, in which itprevents a hooking-in (mounting) or hooking-off (removal) of theconnecting component (5), into a release position permitting ahooking-in or hooking-off of the connecting component.

Therefore, it is an object of the present invention to provide animproved suspension device, particularly in view of the conservation ofthe kinetic energy, reliability and operator convenience, and asuspension system comprising said suspension device.

The problem underlying the present invention is solved by a suspensiondevice comprising the features of claim 1 and by a suspension systemaccording to claim 11. Advantageous further developments of theinvention form the subject-matters of the dependent claims.

The inventive suspension device for a connecting component to which adynamic load is mountable and which forms at least one eye comprises anaxis fixed to a carrier, a roller rotatably mounted on the axis andhaving a circumferential groove into which the connecting component canbe hooked in frictionally, and at least one safety device adapted to bemoved manually from a locking position, in which it prevents ahooking-in or hooking-off of the connecting component, into a releaseposition permitting a hooking-in or hooking-off of the connectingcomponent. Here, dynamic loads cover all kinds of objects mountable tothe connecting component and adapted to be made to move or moving innormal operation. Especially, dynamic load is to refer to a(multi-person) swing which usually moves in an oscillating manner.

In the operating position, the connecting component is frictionallyhooked in the groove extending around the outer circumferential surfaceof the roller, i.e. at least a section of the connecting componentlimiting the eye is in contact with a section of the groove. In thisway, the connecting component is rotatably mounted around the axis viathe roller and can rotate as one piece with the same around the axiswhen a dynamic load, e.g. due to a swing mounted on the connectingcomponent, acts thereon. As, thus, frictional forces only occur in themounting of the roller (preferably a smooth running roller bearing), ahigh conservation of the kinetic energy (i.e. a long maximum duration ofoscillation, particularly desired for swinging) can be achieved. Anoscillating movement of the load is, thus, supported in an optimummanner. The mounting by means of the roller allows a safe accommodationof high dynamic loads. This leads to a high reliability and a long lifeof the suspension device.

The provided safety device, which is adapted to be moved manually,without the use of a tool, from its locking position into its releaseposition exclusively permitting a hooking-in or removal of theconnecting component increases the security and, thus, the reliabilityof the suspension device as well as its operator convenience.Advantageously, the safety device returns to its locking positionautomatically, i.e. by itself. This additionally increases security.

As the connecting component is received in the groove, a movement of theconnecting component and, thus, of a load applied, is impeded from theradial plane of the axis (the plane perpendicular to the axis). That isto say, via the side walls of the groove, a resistance is applied to theconnecting component against a movement in the axial direction. This isparticularly advantageous when using the suspension device in connectionwith swings, as there a swinging movement (oscillating movement) isdesired in one plane only. The higher the force of the weight of theload applied to the connecting component is, the more the connectingcomponent is drawn into the groove and, accordingly, the higher theabove-mentioned effect is.

Preferably, in the hooked-in state, the connecting component is held inthe groove over a circumferential area of the groove of more than 60°,more preferably of more than 90°, still more preferably of more than120°, and further preferably of more than 135°. Advantageously, theconnecting component is clamped into the groove so as to strengthen thefrictional engagement.

Preferably, the dimensions of the connecting component and the grooveare adjusted to each other such that the hooked-in portion of theconnecting component is not loose in the groove and, advantageously,their contours are adjusted to each other. Advantageously, in across-sectional view, more than 50% of the portion of the connectingcomponent deepest in the groove is inside the groove.

The roller is preferably made of an elastic (semi-soft) plastic selectedin dependence on the desired load-bearing capacity of the suspensiondevice. Preferably, the roller is designed such that, if a predeterminednominal load is surpassed by a moving load fastened to the connectingcomponent, the roller is deformed such that it gets into contact withthe axis, thereby exerting a frictional force due to which the movementof the load is decelerated. In this way, excessive load on thesuspension device can be avoided and its life can be prolonged. As analternative, the roller can be made of metal.

Preferably, the groove is arranged in the center, and the rollerconically tapers from its two axial ends to the groove. This has theadvantage that it counter-acts a tilting of the connecting componentfrom the radial plane. Furthermore, the connecting component is, if itjumps out of the groove due to a high lateral force, for example, urgedback into the groove due to the conical tapering towards the center.Instead of the double conical shape, however, the roller may also have acylindrical shape.

Preferably, the carrier has a U-shaped cross-section and is providedwith mounting holes. Preferably, the carrier is mounted on the ceiling,but it may also be mounted on the wall or as support on the ground.

Preferably, the safety device is arranged (coaxially to the roller) onthe axis between the carrier and the roller. Advantageously, the safetydevice protrudes over the outer circumference of the roller in theradial direction of the roller so as to prevent the connecting componentfrom coming off over the roller. Advantageously, a maximum extension ofthe safety device in the radial direction of the roller is larger than amaximum extension of the eye. As the maximum extension of the eye issmaller than the maximum extension of the safety device, the safetydevice forms a stopper for the connecting component so as to prevent thelatter from slipping/coming off over the ends of the roller.

Advantageously, the safety device is designed such that it cannot openduring the operation of the suspension device, i.e. when the dynamicload is hooked in, i.e. does not get unintentionally into the releaseposition. Preferably, the safety device is moved into the releaseposition in the axial direction by a shortening of its length (e.g. bycompression).

Preferably, the safety device applies a spring bias onto the roller inthe axial direction. In this way, the roller can be held in apredetermined position when being in an idle state, i.e. when there isno load suspended or when there is a load suspended but not moving,particularly if safety devices are arranged on both sides of the roller.In addition, movements of the roller in the axial direction can beabsorbed/balanced, i.e. forces acting in the axial direction can betaken up by the safety device, which further enhances the reliability ofthe system. Furthermore, this involves the advantage that the formationof a gap between the roller and the safety device, in which theconnecting component can be hooked off, is reliably prevented.

Advantageously, in its locking position, the safety device is compressedto approximately 50% of its maximum spring travel. Thus, an optimumworking range of the safety device is ensured, i.e. the safety devicecan be lengthened as well as shortened; thereby, on the one hand,movements of the roller in the axial direction can be absorbed/balancedand, on the other hand, a reliable abutment of the roller over theentire range of movement thereof is allowed.

Preferably, the safety device comprises two components spring-biasedagainst each other in the axial direction. Advantageously, the safetydevice is composed of two cylindrical discs and a compression spring(preferably having a conical shape to provide for a low design height ofthe safety device), which is arranged between the discs and biases thediscs against each other. Instead of the two discs, one may e.g. use twobowls having a cylindrical shape which engage with each other and aredisplaceable with respect to each (together with the spring, these thenform a kind of lift cylinder having a variable length), or a combinationof a disc and a cylindrical bowl. It is the advantage of thisconstruction that the safety device can be made of few components in asimple way. With regard to an installation, a disc/bowl (preferably theone having the smaller external diameter) may e.g. directly abut on thecarrier whereas the other disc (preferably the one having the largerexternal diameter) abuts on the inner ring of a roller bearing via whichthe roller is supported on the axis. Preferably, the discs/bowls areformed of plastics so as to keep the manufacturing cost low; they may,however, also be formed of metal.

Preferably, two of the above-described safety devices are provided andare arranged between an axial end of the roller and the carrier,respectively.

The connecting component is preferably formed to be rigid, or rathersolid, e.g. a karabiner, a ring (adapted to be opened), a chain quickrelease fastening element, etc. Yet, the connecting component may be anyother component to which a load can be fastened and which has or formsan opening or rather an eye such that it can be frictionally hooked intothe groove of the roller. Advantageously, the connecting component ismade of metal/steel.

Preferably, the connecting component is adapted to be opened forhooking-in and hooking-off. For this, preferably, a maximally possibleopening is less than the minimum external diameter of the roller andlarger than the maximum diameter of the axis.

In the following, the invention will be described by means of preferredembodiments with reference being made to the Figures.

FIG. 1 is a schematic diagram of a perspective view of the suspensiondevice according to the invention.

FIG. 2 is a schematic diagram of a front view of the suspension deviceaccording to the invention.

FIG. 3 a is a sketch of a lateral view of a roller of the suspensiondevice according to the invention.

FIG. 3 b is a cross-sectional sketch of a safety device of thesuspension device according to the invention.

First of all, with reference to FIGS. 1 and 2, a preferred embodiment ofthe suspension device according to the invention is described. Thisbasically consists of a carrier 1, an axis 2, a roller 3, two safetydevices 4 and a connecting component 5.

The carrier 1, here: a carrier for a ceiling suspension, has a U-shapeand comprises a base plate having bore holes for being mounted to theceiling and two legs arranged at a 90° angle to the base plate. The twolegs of the carrier 1 hold the rigid axis in a fixed manner; forexample, the axis 2 is plugged and clamped into the carrier, or iswelded thereon. The roller 3 and the two safety devices 4 are pushedonto the axis 2.

As is shown in FIG. 3 a, the roller 3, which is formed of an elasticplastic, has a centrally arranged groove extending around the outercircumference thereof, and is tapered in a conical shape from its twoaxial ends to the groove; however, the roller 3 instead of tapering mayalso be formed in a cylindrical shape. Furthermore, the broken lines inFIG. 3 a serve to suggest two roller bearings via which the roller 3 ismounted so as to be rotatable around the axis and displaceable in theaxial direction (an inner diameter of the roller bearing is larger thanthe diameter of the axis). The construction with the two roller bearingsinvolves the advantage that, compared to the application of force to onepoint, a local bending stress is reduced, as a load applied by theconnecting component 5 to the roller 3 is transmitted to the axis viathe two roller bearings, i.e. is distributed to two transmission points.This, in turn, increases the safety and the reliability of the wholedevice.

The suspension device according to the present embodiment comprises twoidentically constructed safety devices 4 mounted in a mirror-invertedmanner, each of which is arranged between a leg of the carrier 1 and anaxial end of the roller 3. In the following, the basic construction ofsuch a safety device 4 is described with reference to FIG. 3 b, inparticular, this figure showing a cross-section of the safety device 4.As is shown in FIG. 3 b, the safety device is composed of twocylindrical discs having a central bore hole and a conically shapedcompression spring which is arranged in between and biases the discsagainst each other. One disc is recessed so as to provide a spring seatfor the compression spring. Preferably, the recess is dimensioned suchthat the discs can (partly) be fitted into each other, i.e. the safetydevice forms a kind of lifting cylinder with an increasable/reduciblelength in the axial direction.

In the mounted state (cf. FIGS. 1 and 2), in which the discs are pluggedvia their bore holes onto the axis 2 and are slidably supported, thedisc having the smaller diameter abuts on the leg of the carrier 1, andthe disc having the larger diameter abuts on the inner ring of theroller bearing via the circumferential protrusion shown in FIG. 3 b (ora spacer). That is, the safety device only contacts the inner ring ofthe roller bearing, but not the roller 3, so that a rotation of theroller 3 is not obstructed. The axial length of the protrusion or spaceris dimensioned such that the distance between the disc having the largediameter and the axial end face of the roller is minimal (preferablyless than 1 mm).

The external diameter of the larger disc has been selected such that itprotrudes over the outer circumference of the roller in the radialdirection of the roller 3, as shows FIG. 2. As is described furtherbelow, this protrusion prevents a lateral jumping-off of the connectingcomponent 5 off the roller 3. Preferably, in the installed state (andwith the load not being fastened), each safety device 4 is compressed toapproximately 50% of its maximum spring travel. As can be seen from FIG.2, the spring bias of both safety devices 4 has been selected to beequally large, so that the roller is held centrally on the axis 2 at thesame distance to the legs of the carrier 1.

In this embodiment, the connecting component 5 is a karabiner made ofsteel; the inner area limited by the contour of the karabiner is the“eye” thereof. At its upper end, the connecting component 5 is hookedinto the groove of the roller 3, as shows FIG. 1. The contours orprofiles of the connecting component 5 and the groove are preferablyadjusted such that they provide for a certain clamping effect betweenthe groove and the connecting component 5.

As already indicated above, the maximum extension of the eye of theconnecting component 5 is smaller than the outer diameter of the largerdiscs of the safety devices 4, so that the discs form a stopper for theconnecting component 5 in the axial direction of the roller 3 and, inthis way, prevent a slipping/coming off of the connecting component overthe axial ends of the roller 3.

A load, such as a (multi-person) swing, is hooked in/fastened to the endof the connecting component 5 that is not hooked in the roller 3 (at thelower end in FIG. 1).

In the following, the mode of operation and the operational states ofthe suspension device according to the embodiment will be described.

First of all, the mode of operation and the operational states in loadoperation are described; here, load operation is to refer to a state inwhich a load, such as a swing, is attached to the connecting component5.

In the idle state, i.e. when the load is not moved, the weight of theload causes the connecting component 5 to be further pressed into thegroove of the roller 3 so as to be securely held therein. The weightforce of the load is applied via the connecting component 5 directlyonto the roller 3 and, from there, via the axis 2 into the carrier 1.

When the load makes an oscillating movement around the axis 2, thefrictional engagement makes the connecting component 5 rotate as onepiece with the roller 3 around the axis 2. As, thus, a frictional forceis only produced at the bearing of the roller 3, the largest possibleconservation of the kinetic energy, i.e. the swinging movement, can beachieved. Moreover, a material fatigue, particularly of the connectingcomponent 5, can be avoided in an advantageous manner.

If a static or dynamic load exceeds a predetermined load-bearingcapacity, the roller 3 is deformed and is pressed against the axis 2 atits inner circumferential surface. This causes an increase in friction,so that a dynamic load is decelerated and, as the case may be, is slowlybrought to a standstill. In this way, an overload on the suspensiondevice is avoided.

Next, the mode of operation of the suspension device in the case oflaterally acting forces is described, said forces being transmitted tothe roller 3 via the connecting component 5. In this connection,laterally acting forces are forces substantially acting in the directionof the axis 2 and being caused for instance by a movement of the load inthis direction.

When the laterally acting forces are small, the connecting component 5remains in the groove and does not or hardly tilt from the radial plane(the plane perpendicular to the axis 2), as the groove, particularly itsside walls, applies a counterforce working against the acting force. Inthis way, a stable operational position is ensured.

When the laterally acting forces are rather large, the part of theconnecting component 5 which is hooked in the groove (the upper part inFIG. 1) largely remains in the groove, whereas the opposite part (thelower part in FIG. 1) of the connecting component 5 tilts out of theradial plane. The tilting is limited by the safety device 4. Especially,as from a specific tilting degree, the lower end of the connectingcomponent 5 abuts on a disc having a rather large diameter of the safetydevices 4, thereby preventing a further tilting. When the laterallyacting force subsequently gets smaller again, the connecting componenttilts back into its original position, i.e. into a position as the oneshown in FIG. 2, the tilting being supported by the conical shape of theroller 3.

Very large laterally acting forces, which are caused, for example, by anabrupt change of load, may lead to the connecting component 5 jumpingout of the groove. In this case, too, the safety devices 4 prevent aslipping of the connecting component 5 down over the axial ends of theroller 3, as their external diameter is larger than a maximum extensionof the eye of the connecting component 5. When the laterally actingforce slackens, the connecting component 5 moves back into the grooveinto its original position, as shows FIG. 2 (back into the radialplane), this movement in turn being supported by the conical shape ofthe roller 3.

Additionally, movements of the roller 3 on the axis areabsorbed/balanced by the safety devices 4 due to laterally actingforces. This means, laterally occurring forces may, in principle, causea shifting of the roller 3 to an outermost position on a leg of thecarrier. When this occurs, a safety device 4 is maximally compressed inthe axial direction while the other safety device 4 becomes maximallyenlarged in the axial direction. Accordingly, all parts on the axis 2remain under tension due to the springs provided in the safety devices4, i.e. no gap is formed in the axial direction between the axial endsof the roller 3 and the safety devices 4. Therefore, a high level ofsecurity against an unintended hooking off/coming off of the connectingcomponent 5 is provided.

Next, it will be described how the connecting component 5 is hooked intoand hooked off (detached from) the groove.

In order to improve security even further, hooking in and hooking offthe connecting component 5 is exclusively possible by operating one ofthe safety devices 4. For hooking in, the roller 3 is held tight and oneof the safety devices 4 is compressed (for example, directly by hand orby the connecting component 5 held in the hand), so that a gap in whichthe axis 2 is exposed is formed in the axial direction between theroller 3 and the safety device 4 (release position).

In the next step, the opened connecting component 5 is hooked in thisgap into the axis 2. In this context, it has to be mentioned that,according to the invention, a maximally possible opening range of theconnecting component 5 has to be dimensioned such that the connectingcomponent 5 can exclusively be hooked in/off on the axis 2 and cannotdirectly be hooked into/off the groove of the roller 3.

After the connecting component 5 has been hooked in on the axis 2, theconnecting component 5 is closed, lifted over an axial end of the roller3 and inserted into the groove. When the connecting component is liftedover the axial end of the roller 3, the gap automatically closes due tothe spring bias of the safety device 4, and the safety device 4 is onceagain in its locking position.

Removing the connecting component 5 takes place in reverse order.

As has already been described above, it is not possible in the operatingstate to detach the connecting component directly from the roller 3(“hook it off”), as all diameters of the roller 3 and all openingdimensions of the connecting component 5 are adjusted to each other suchthat the connecting component 5 cannot be opened or cannot be opened farenough for allowing it to get hooked off.

The present embodiment offers the following advantages:

The frictional accommodation of the connecting component 5 in thecircumferential groove of the roller 3 supported on the axis 2 by meansof roller bearings provides a very high conservation of the kineticenergy in an oscillation plane while movements in a lateral directionthereto are impeded, which is particularly advantageous for a use inconnection with swings.

The suspension device offers a high degree of security and reliability.On the one hand, the mounting by means of the roller 3 allows a safeaccommodation of large and permanent loads. On the other hand, thesafety device 4 takes care that the connecting component 5 can easily behooked in and off, but that an unintentional hooking off of theconnecting component 5 is avoided. Furthermore, the safety device 4 isadapted to absorb laterally acting forces.

A manual hooking in and off of the connecting component 5 is possiblewithout any further auxiliary means being required, so that a maximumoperator convenience is ensured.

Moreover, the suspension device according to the invention is composedof very few individual parts, which can be produced at low cost and canbe mounted very easily.

In addition, the mounting via the roller 3 makes the suspension devicework with hardly a sound being produced.

In particular, the suspension device according to the invention isextremely advantageous for use with swings, as it supports anoscillating movement in the radial direction around the axis 2 whileimpeding or cushioning transverse movements thereto.

An additional safety aspect is provided by the connecting component 5still being held by the axis 2 even if, for instance, the roller 3 orthe discs of the safety devices 4 should break due to an overload. Thisis of special significance for swings so as to minimize the risk ofgetting injured.

Although the suspension device of the above embodiment comprises twosafety devices 4, it is also possible to provide one safety device 4only.

The use of the suspension device according to the invention is notlimited to a suspension of swings—although this is preferred. Forinstance, the suspension device is adapted to be used for guiding longgoods/rods. When this is done, the long goods/rods can be guided in thegroove of the roller 3, the resilient safety devices allowing a play/acertain movement in the transverse direction. The suspension deviceaccording to the invention is adapted to be mounted on the ceiling, onthe wall, and as support on the ground, as well. It may also be mountedon existing profile rail systems at standardized distances.

Furthermore, the suspension device according to the invention is adaptedto be incorporated into an automotive component, which moves loads, orinto an automatic sensing component for controlling movements and foradjusting the suspension height of loads, particularly for the controlof individual rope lengths. In this context, it is further conceivablethat influence may also be exerted on the angle of inclination of thesuspended loads.

The materials used may be selected depending on the purpose, e.g. foroutdoor applications, possibly near the sea, weather-proof materials,such as high-grade steel, may be used.

Although the embodiment shown describes the variant according to whichthe connecting component 5 can be opened to be hooked into the axis 2,it is also possible to use a closed connecting component, such as aring, which can be hooked in by pulling the axis 2 partly out of thecarrier.

1. A suspension device for a connecting component (5) to which a dynamicload is mountable and which forms at least one eye, the suspensiondevice comprising an axis (2) fixed to a carrier (1), a roller (3)mounted on the axis (2) so as to be rotatable and having acircumferential groove into which the connecting component (5) can behooked in frictionally, and at least one safety device (4) adapted to bemoved manually from a locking position, in which it prevents ahooking-in or hooking-off of the connecting component (5), into arelease position permitting a hooking-in or hooking-off of theconnecting component (5).
 2. The suspension device according to claim 1,characterized in that the safety device (4) automatically changes fromthe release position back to the locking position.
 3. The suspensiondevice according to claim 1 or 2, characterized in that the safetydevice (4) is arranged on the axis (2) and protrudes beyond the outercircumference of the roller (3) in the radial direction of the roller(3).
 4. The suspension device according to claim 1 or 2, characterizedin that the safety device (4) is moved to the release position by ashortening of its length in the axial direction.
 5. The suspensiondevice according to claim 1 or 2, characterized in that the safetydevice (4) applies a spring bias to the roller (3) in the axialdirection.
 6. The suspension device according to claim 5, characterizedin that, in its locking position, the safety device (4) is compressed toapproximately 50% of its maximum spring travel.
 7. The suspension deviceaccording to claim 1 or 2, characterized in that the safety device (4)comprises two components which are spring-biased against each other inthe axial direction.
 8. The suspension device according to claim 1 or 2,characterized in that the safety device (4) is composed of two discsslidably arranged on the axis and a compression spring biasing the discsagainst each other.
 9. The suspension device according to claim 1 or 2,characterized in that two of the safety devices (4) are provided, eachbeing arranged between an axial end of the roller (3) and the carrier(1).
 10. A suspension system, comprising the suspension device accordingto claim 1 or 2, and the connecting component (5) to which a dynamicload is mountable and which forms at least one eye.
 11. The suspensionsystem according to claim 10, characterized in that a maximum extensionof the safety device (4) in the radial direction of the roller (3) islarger than a maximum extension of the eye.